Heater



FIG. 1 is a left, front, top perspective view of a heater in accordance with the present invention;

FIG. 2 is an elevation view of the left and rear sides thereof;

FIG. 3 is an elevation view of the right and front sides thereof;

FIG. 4 is an elevation view of the right and rear sides thereof;

FIG. 5 is an elevation view of the front and left sides thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines represent portions of the structure that form no part of the claim. 

CLAIM We claim the ornamental design for a heater, as shown and described. 